If you get me, and I think that's right! Perhaps Tolkien was just a bit too polite to mention any Elves that where ugly and so simply ommited that fact from any of the annals, he just didn't say they where handsome!

while all elves were more or less fair of face, when he mentions that this one or that one is handsome by name, he means by elf standards? Which means that there is such a thing as a flawed elf, if not necessarily ugly...

So in the eyes of the elves, there were some who were plain janes, and others who were gorgeous- thus, elves did indeed vary in just HOW beautiful they were or not.

However, because of the light shining within them that is more obvious/less subtle than mortals, to mortals they are all at the very least pretty, with some elven maids just to gorgeous for words

Or maybe elves are just exotic and mysterious to other races, and by extension all elves to mortal eyes are beautiful...even if elves do not think so.

So maybe Nerdanel would be considered plain to elves, but by mortal standards she was still passably pretty, even if she was clearly no Luthien. But because she was an elf, mortals would still be in awe simply because of her race. Or it could simply be that, if there were any plainer elven women that the hobbits encountered, they didn't notice because they were too busy gawking at Arwen and Galadriel to pay the others much mind

As far as Legolas and the other elven men go, I think they would be considered fair of face by mortals simply because they were paler/ not tan or sunburnt and not scruffy like mortal Men were (and again, that whole light thing...). Keep in mind that Aragorn and his clothing was very dirty when the hobbits first met him, but when he was clean he was far more fair-and in the books, he didn't have a beard either. Plus, Legolas could carry a tune very well, whereas as we all know, in the world of Men there are some that can sing beautifully, and others that can't carry a tune if you paid them to do so.

But overall, the generalization that all elves are beautiful and fair of face and song, may simply be reflecting the authorial bias the hobbits had toward elves, based upon the exotic and mysterious factor, and the fact that the specific elves they encountered were, even if that's not necessarily reflective of ALL elves in ME and Valinor. My writing and novels:

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